(1) Field of the Invention
The present invention concerns a machine for binding a packet of perforated sheets and a method of binding a packet of perforated sheets implemented in such a binding machine.
(2) Prior Art
In the field of machines for binding packets of perforated sheets, some of them use particular binding elements. FIG. 10 shows an example of these binding elements 206. These binding elements 206 are in the form of a metal wire curved so as to form a series of fingers curved in the form of a hairpin. Each binding element 206 has a closed end 604, also referred to as the “point”, an open end 602, also referred to as the “base”, and an intermediate zone 606 that is designed to deform when the said binding element 206 is closed. The perforated sheets are engaged on the points 604 and each finger is deformed in an annular form by approaching the point 604 close to the bases 602.
The binding machine bearing the reference Wir-O® Bind 3500 uses such binding elements 206. This binding machine comprises amongst other things:                a station for supplying binding elements,        a station for cutting the binding elements,        a device for transferring the binding elements,        a station for assembling the packet of perforated sheets on the binding elements,        a station for closing the binding elements thus assembled with the packet of sheets, and        a station for discharging the bound assembly.        
The transfer device is in the form of a transfer belt forming a loop, which is magnetic so that the binding elements are fixed thereto. The transfer device receives cut binding elements at the discharge from the cutting station and transfers them successively through the assembly station, the closure station and the discharge station.
This binding machine has the disadvantage that assembling the sheets on the binding elements takes place manually, that is to say a technician must engage each point in the appropriate hole in the packet of sheets. This is because, since the points are not fixed, it is necessary, before closing the binding elements, to ensure that the packet of perforated sheets is correctly positioned.
In addition, this step is often lengthy, giving rise to a drop in the bound-assembly production rates.